How bad of an idea is it to cut structure out of my lathe base?

[Redneck_Sophistication]

That drawing looks about right.
The tail end seems to be one piece collar inserted into the end plate, no bearing

The spindle is so stiff I can loosen the locking collars with out spinning the spindle.
The collar on the second gear was pretty mushroomed it’s been worked on before. There was only a brass spacer on one of two set screws on the collar of the feed gear, the middle bearing looks straight to me. Not a tapered baring. It’s also not on a shoulder just a floating collar against the drive gear

With all the collars off it’s still just as tight.

I’ve got up to the bull gear and it doesn’t want to move.

I’ve rotated it around tapping on it with a nylon block, got in with two pry bars on either side.
I used a thin
Sharpened chisel between the gear and spacer it popped off ok

I tried to get the chisel behind the bull gear, and the spacer or what ever it is behind it moved very easily (no hammer) but the gear didn’t move. Not sure where to go from here, sure don’t want to damage anything.

I put a nylon block on three of the spindle and gave it a few light Taps just to see if there was any movement but nothing.

There is a pump on the main shaft, the plastic line going down is damaged it looks like it was hitting a gear.

I feel like there are further screws behind the chuck collar holding the plate on (chisel gets some movement away from this area but nothing nearby)

 

[RobinHood]

Thanks for the pictures.

Let’s start at the rear of the spindle.

This looks to be the rear oil slinger ring (you “oil seal”). Presently it is not located properly - it would need to be further back on the spindle, inside the HS housing, but not touching the rear shoulder of the casting.

This is a floating bearing (maybe roller, can’t tell). It allows for thermal compensation of the spindle. The bearing is retained on the spindle by the rear collar.

Backing off the front collar (the one that is a bit chewed up) allowed you to slide the second gear and the intermediate sleeve rearwards (one of the pictures shows a nice large gap).

You were able to move the bull gear a wee bit as shown in this picture.

It is probably hung up on either splines or a key. It would be a very close tolerance fit onto the spindle. Yes, using two pry bars on opposite sides does help, but the slightest uneven pressure will jam it up.

There is probably a double row, tapered roller bearing in here (red box).

Something like this:

The front plate may have threaded holes for jacking screws - could be these. Remove the paint to check.

If they are threaded, put in 4 bolts and carefully put pressure on them in order to separate the plate from the HS main casting. Everything is aluminum - so I would be extremely careful not to damage anything. The seal is probably RTV which is brutal to pull apart in tension; it is easier to get apart in shear, but there may be locating pins holding the plate onto the HS. Use a heat gun to warm things up if needed.

I would make myself a spindle puller using ready rod. I would use 3/8”. Make a plug to fit over the rear spindle with a hole in the center for the RR. At the nose end use a beefy angle to span across the HS and block it only at the edge (outside of the front plate). Make a wooden plug with a hole in the center for the spindle nose to centralize the RR. Put light pressure on the rod, just so that things stay in place. Turn the jacking bolts (if there are in the plate) and the nut on the RR a bit at a time to put pressure on it and then use your plastic hammer to tap the bull gear. Check for spindle movement out the front. It will only move a tiny bit at a time - but that is ok. You can also tell if things move if the tension on the RR nut has decreased after tapping the spindle components. If you can, turn the spindle 90* after each “pull”.

Your set-up could look something like this:

Here I am re-installing the spindle on my big lathe; to pull it out, the puller was on the opposite side, same principle though.

As the components slide off their seats, it becomes easier to pull. Put rags under any components so when they do come off, they don’t fall down into the HS below and jam up. Take lots of pictures as you get the bits out starting with the slinger ring.

The oil pump probably just needs a new pick-up tube.

Sorry for the lengthy post. I don’t know of a good video to show the process…

 

[RobinHood]

Forgot to mention: put hardwood wedges between the bull gear and the HS casting where the green arrows are before you start to pull. They take the place of your pry bars.

 

[Redneck_Sophistication]

Good tips!
Good eye on the possible jack
Screws I’ll check that out

Would putting a threaded rod through the spindle to the tailstock be a bad idea? It’s a pretty beefy tailstock. Or if not to the tailstock itself but that end and tighten the nut on the spindle end with a steel plate to push it out?

I think
I’ve got a big Length of 1/2” and some 5/8th round rod with threaded ends.

A couple corrections on your comments on the pictures as I wasn’t clear uploaded them (all this is on my phone)

The “rear oil slinger” ring is shown after I removed it from the socket. That entire tapered section was inside the HS casting. It is one piece with the slightly smaller section and held in place with one set screw(one missing)

The bull gear did not move AT ALL I went in there with my thin chisel and that other piece (collar, or bearing race) moved easily away towards the chuck. It was not a a tight tolerance, I pried at the top and it opened that much but the bottom was still tight.

 

[RobinHood]

I’ve got a big Length of 1/2” and some 5/8th round rod with threaded ends.

Sure, use what you have. The larger the RR the easier it is to bust something…

I would not use the tail stock as an anchor point, however beefy it is. Keep the forces close to the HS casting side walls.

The “rear oil slinger” ring is shown after I removed it from the socket. That entire tapered section was inside the HS casting. It is one piece with the slightly smaller section and held in place with one set screw(one missing)

That’s even better, so it was in its proper spot before you started investigating.

The bull gear did not move AT ALL I went in there with my thin chisel and that other piece (collar, or bearing race) moved easily away towards the chuck. It was not a a tight tolerance, I pried at the top and it opened that much but the bottom was still tight.

So it probably is just a spacer ring as you suggest. Something must have moved though after you undid the locking collar behind the second gear (btw, I just called it that because it is the “second” gear on the spindle behind the bull gear. There probably is a technical term for it, but I don’t know what that would be).

So if the spacer moved towards the chuck end of the spindle and if there is no other bearing pre-load ring behind it, at least one of the bearing cones should be free to move out of its cup a bit, loosening up the spindle. Hmm... Did you give the spindle a little tap from behind (use a soft hammer or a block of wood and a regular hammer) after you backed off both collars? It might be worth to do that in order to see if you can unseat the front cone as well. Once both cones are loose, the spindle should turn freely and you should be able to feel radial play at the spindle nose. If it is still tight, then the rear bearing is the one hanging up.

Still does not explain why the bull gear does not want to move…

Oh, another thing: when you try to turn the spindle by hand, did you also disengage the feed gear? Just move the handles and see what lever and which position you have to move them to so that you have no gears in mesh on the spindle.

 

[Redneck_Sophistication]

The spindle is totally out of gear mesh. I can turn the motor on and only the firsts shaft spins.

After everything was loosened I did tap the spindle from the back
With a 2lbs hammer and nylon block. No movement, but I’m being cautious. I’m generally a little destructive, so I’m trying to take it slow. Take a step back, consult with the experts here, reassess and try some more.

Can’t even find a picture of the lathe online. No way your going to find parts!

One thing I had to triple check was the main gear collar was right hand thread. The rear was left hand. Hard to see with only half a thread past the collar

 

[RobinHood]

Nothing wrong with taking it slow. If in doubt stop and re-evaluate.

 

[Redneck_Sophistication]

Evidently my chimney was to small to fit a new lathe down so we continue the repair

The set up:

Front of HS is rounded off nothing to attach/rest a pulling plate to.

Well let’s see!

 

[Redneck_Sophistication]

About 20thou of progress!

 

[RobinHood]

That looks like a reasonable set-up. Slow and steady will win the race. Lots of tapping with the soft blow to allow the stresses to equalize and the bull gear / bearing and all other components to slide along the spindle shaft.

 

[Redneck_Sophistication]

Bull is really the only hold up. Face plate is loose can spin it.

The “jack screws” were nothing 8/32 looks like done by hand and half stripped. Didn’t go through the plate. Maybe an old mount for a shield?

Got about 1/4” of movement. Crank the clamps. Tapping abs oil all around then tap the steel push plate with hammer and repeat.

Just took the clamps off and spun everything make sure I’m not binding on something

 

[Redneck_Sophistication]

Well that was hard earned let me tell you!

Bull gear was tight over the entire journal, but also the rear roller-bearing it left some lite scoring on the shaft as it moved:

There is also very narrow opportunity to remove keys, I’ll have to watch that on reassembly

Once stuff opened up it looked like the bearing were rusty, but I
Think it’s nasty congealed old oil.
Maybe this thing was sitting for years or decades and gummed up the bearings.

The bearings and races seem to be in good shape no scoring save one spot on the rear baring race where a small piece looks to have spalled off.

I thought it was just grime but upon cleaning the void was packed with it.

Front:

A couple small casualties:
The rear oil slinger
Was binding when it was half off the spindle tapped with a small piece of wood and snapped a piece off. Wasn’t expecting an aluminum part, with the grain structure that looks cast

This tapered piece was between the bull gear and the race of the main bearing, oil slinger ??
Pushing the spindle caused it to push against the race marring it a bit. But I don’t think this is critical.

I can access the oil pump now at least. Not sure how to remove
The pick up tube is worn right through, it had a screen on it that was pretty jammed and very small.
Having this on there seemed strange to me, it’s several inches off the bottom, and not exactly serviceable, this could lead to starving it for oil.

I’m hoping I can clean all the crud from the main bearing and reassemble. Or should I replace the bearings having come this far?

There was also no seal of any kind on the HS plate, just paint that leaked in

 

[Dabbler]

Anyone else watch Cutting Edge Engineering on YouTube?

I was following that thread. He brilliantly diagnosed it as being SEP and brought in an electrical specialist and they fixed the problem for him (at a cost, of course)

Knowing when the problem was beyond his skills was key here. Great guy - love his channel.

Great work on the lathe BTW. It is really going to be a beaut when it is done...

 

[RobinHood]

There you go. Good job getting it out.

The rear slinger ring looks to be cast iron (based on the grain structure). You can test is with a magnet to confirm.

That is a nasty chip out of the rear bearing outer race for sure. If you suspect that is from corrosion, then there probably is a corresponding roller(s) with some pitting on it as well.

Carefully cleaning the bearings should reveal the condition. if you can find numbers on the bearings, you could try and source new ones. I’d be sitting down for when you receive a quote - these things are typically very expensive. Some bearings have modern equivalents which could be in a better price class. Post the bearing details if you need help.

Those “scratch marks “ on the spindle will require stoning off prior to assembly as they will give you grief and damage the mating parts.

Good that you have clear access to the oil pump now. I would suggest inspecting and verifying proper operation before you put the spindle back in. Since it is driven off the input shaft, it will pump oil any time the motor runs. Good way to test operation. Perhaps cover the HS opening with some cardboard during testing as the oil will fly everywhere once the pump is operating properly (ask how I learned that one the hard way…).

I think our observation about possible oil starvation is bang on: if the pick-up tube screen is plugged up, the main bearings will receive less than the required amount of oil as the pump is not supplying it in sufficient quantity any more. Some still gets to them from splash lubrication.

Could be that there was a “cardboard” type seal behind the HS cover plate. It should suffice as the oil is only splashing out of the bearing and is not really under pressure. Looks like the oil runs down from the main bearing to the three shaft bearings below before it returns to the sump.

 

[Redneck_Sophistication]

The slinger is definitely not iron.
Aluminum or magnesium maybe as it is super light weight even for aluminum I’ll do an acid test to see. Hopefully it’s not a nasty alloy going to try and repair the piece back on or build it back up with AC-TIG.

That ‘chip’ in the race is odd. It’s not corrosion I don’t think. It looks like it spalled OUT of the race. Almost like a bad forge weld would. Close inspection of the rollers look good. Temping to reuse. Need a closer look at the main yet, if it’s good I’d rather not have to remove it. Looks like a pain and more if one to reinstall.

Agreed I’ll be stoning off those scratches.

I suppose there could have been some type of gasket that was previously removed. I was thinking light application of RTV on install.

Interestingly enough there is an oil drain on the main bearing at 6 o’clock on the inboard side of the race. Doesn’t look like it flows down the plate at all, I would think there would be some pathways cut into the HS or plate.


I did a quick look on McMaster-Carr for the bearings by number (haven’t measured them yet) they did not have a match

If anyones google-fu is up for it

Rear: timken
outer race:33820B
Inner race: 33890
Looks like it was electo-penciled with : //-25-53-0 on the inner race not sure what that’s about

Main bearing: Timken
Outer: 39520B
Inner: 39590

 

[Redneck_Sophistication]

Well I retract my previous statement the main bearing is NOT hard to get out. I thought I’d have to make a whole puller for it. Two pry bars on the HS plate and it popped right off.
Extra gungy too.

 

[RobinHood]

Here is a reference for the outer race of the rear bearing:

Part Number 33820-B, Tapered Roller Bearings - Single Flanged Cups - Imperial On The Timken Company

Browse Part Number 33820-B, Tapered Roller Bearings - Single Flanged Cups - Imperial in the The Timken Company catalog including Part Number,Item Name,Description,Series,Cup Part Number,Design Units,D - Cup Outer Diameter,D1 - Flange Outer Diameter,C

cad.timken.com

and for the inner race:

Part Number 33890, Tapered Roller Bearings - Single Cones - Imperial On The Timken Company

Browse Part Number 33890, Tapered Roller Bearings - Single Cones - Imperial in the The Timken Company catalog including Part Number,Item Name,Description,Series,Cone Part Number,Design Units,d - Cone Bore,B - Cone Width,R - Cone Backface "To Clear" R

cad.timken.com

For the main bearing, outer race:

Part Number 39520-B, Tapered Roller Bearings - Single Flanged Cups - Imperial On The Timken Company

Browse Part Number 39520-B, Tapered Roller Bearings - Single Flanged Cups - Imperial in the The Timken Company catalog including Part Number,Item Name,Description,Series,Cup Part Number,Design Units,D - Cup Outer Diameter,D1 - Flange Outer Diameter,C

cad.timken.com

and for the inner race:

Part Number 39590, Tapered Roller Bearings - Single Cones - Imperial On The Timken Company

Browse Part Number 39590, Tapered Roller Bearings - Single Cones - Imperial in the The Timken Company catalog including Part Number,Item Name,Description,Series,Cone Part Number,Design Units,d - Cone Bore,B - Cone Width,R - Cone Backface "To Clear" R

cad.timken.com

Slinger ring: good call on it being magnesium, it would explain the grainy surface where it broke.

Oil drain: makes a lot of sense, should allow for relatively easy sealing of the front plate. RTV will work.

“//-25-53-0“ could be a date code, like 25th day (or week) of 1953? Guessing here.

I wonder if that “spot” on the rear bearing outer race is a chip that “welded” itself to it? If something got into the bearing while it was running, it could just get flattened by the rollers onto the race?

After you clean the bearings thoroughly, I would reassemble the spindle into the HS without any of the components which require pressing on (bull gear). For any components you leave off, make a spacer sleeve. What you are trying to find out is if you can set the bearing pre-loads with the collars and get the spindle to turn smoothly. If you get that, I would remove the spindle, clean everything really well again and reassemble with all the components. Set the preload and call it good.

If the bearings are bad, you’ll have to hunt some down from your favourite bearing supplier.

 

[YYCHM]

@RobinHood , If the slinger ring is magnesium can it be repaired?

 

[YotaBota]

If you're going to be keeping the machine I would replace the bearings (if cost effective). Knowing what a pita it is to take apart and if it is to be your main goto machine, I think it would be better to do it now than be wondering when the bearings are going to go bad. The divot in the race would be a worry for me.

 

[Dabbler]

@RobinHood , If the slinger ring is magnesium can it be repaired?

It can be repaired - I knew a guy that could weld magnesium, but the trouble it would take isn't worth 8 dollars of 6061 aluminum.

@Redneck_Sophistication some (non-lathe) machines use magnesium as a cathode - is this possibly a dual purpose item? The you'd best be making it out of zinc if it is. Frankly if it were my machine I'd give 6061 a go and keep an eye on it and the gears.